A person will frequently leave an infant, toddler, or pet within a car with the expectation that his or her time away from the car is not long enough to allow any hazard to the individual or animal within; however, the person may be delayed in his or her business. Furthermore, it can often be difficult for an individual to know where the line is between safe and unsafe conditions within the passenger compartment while he or she is not there. Unfortunately, too many times, the child or pet comes to harm because the environment within the car becomes unsafe. High temperatures are usually the culprit of the hazardous environment; however, other potential dangers exist such as freezing temperatures, high levels of carbon monoxide (CO) when the engine is left running, or people who pose a threat to the child or pet.
Although car alarms are available for burglar entry sensing, theft deterrence, or theft protection, these alarms are only capable of sensing automobile motion, shock, motion in the interior passenger compartment, or forced entry. They do not sense passenger compartment temperature or other conditions relating to an occupant""s environment. Furthermore, the type of sound emitted by such car alarms is non-descriptive, so the sound produced by such alarms would provide little measure of safety for an infant caught inside a hot vehicle.
Inside a home, infants and toddlers are often monitored using baby monitors. FIG. 1 illustrates a typical baby monitor in block diagram form. It comprises two sections. The first section 100 comprises a microphone 110, a pre-amplifier 120, a transmitter 140, and a power supply 180. The second section comprises a receiver 200, and a loudspeaker or headphones 210. The power supply 180 is designed for use with small batteries and/or household voltage 300. It is not designed to operate from a 12 V car battery, or to plug into a cigarette lighter. Such baby monitors are designed primarily for use inside a home, and they are only designed to detect sound. The adult at the receiving end of the monitor 200 can thus often tell when a child has awakened or possibly when a child has been injured, but the adult is unaware of temperature or other environmental factors at the transmitter end. While such baby monitors are often adequate for the controlled environment of a typical home, the environment inside a motor vehicle is much less controlled, and a pet or sleeping child would be unable to report dangerous conditions to an adult listening at the other end of a standard baby monitor.
It is therefore an object of this invention to overcome the shortcomings of the prior art by providing a system which can sense dangerous conditions within a vehicle, and appropriately warn someone to come to the aid of a helpless passenger. To fulfill the object, the system is equipped with one or more sensing devices such as temperature sensors, CO sensors, microphones, or equipment for detecting motion near the exterior of the vehicle. The system is also equipped with apparatus that will appropriately warn someone of the dangerous condition in such a way as to instigate action.
The first and preferred embodiment of the invention comprises an enhanced baby monitor system, designed especially for use in vehicles, in which the transmitter comprises a temperature sensor, a CO sensor, and a means for conveying information about temperature and CO content along with the sound detected by its microphone. This embodiment also allows for an array of external motion detectors to be plugged into it in order to detect a person trying to break into the vehicle and thus pose a threat to the vehicle occupant.
Another embodiment comprises an enhanced car alarm system which comprises temperature sensors and CO sensors located inside the vehicle, as well as sensors to detect motion in the vicinity of the vehicle. The alarm also comprises means to convey information about a dangerous condition in the form of simulated voice, so that in the event of a dangerous condition, the alarm broadcasts a standard alarm sound alternated with the simulated voice as well as amplifying the sound inside the vehicle, such as a crying child.
A third embodiment of the invention comprises an environmental warning module which can attach to a wireless telephone. When a dangerous condition is sensed, the module uses the wireless telephone to report a message to a remotely located person. The message is reported through another telephone or through a pager.